1. Field of the Invention
This invention relates to process and apparatus for measuring and monitoring muscle compartment pressure or interstitial tissue pressure.
Interstitial tissue pressure measuring and monitoring is useful for diagnosis and amelioration of the effects of acute compartment syndromes. Trauma can cause the pressure in tissue confined within a body compartment to increase to a level which is uncomfortable or causes muscle and nerve damage. It is desired to diagnose this pressure build-up as soon as possible so that corrective procedures can be performed to remove the excess fluid, thereby reducing the harmful pressure and preventing permanent damage.
2. Discussion of Prior Art
U.S. Pat. No. 4,423,740, granted Jan. 3, 1984 to Castle et al, discloses "An interstitial tissue measuring device comprising a cannula and a catheter, the catheter being adapted to pass through the cannula and the distal end of the catheter being provided with a plurality of longitudinal slits defining a plurality of petals between them. When the cannula is emplaced in an interstitial tissue site and the catheter is passed through the emplaced cannula into the tissue, the petals facilitate measurement of pressure by a pressure-sensing device at the proximal end of the catheter". The pressure sensing device is only identified as such and is not described in any manner. The claims of the patent are directed to the method of using the described device.
U.S. Pat. No. 4,185,641, granted Jan. 29, 1980 to Minior et al, relates to a pressure dome which is provided with resilient tongues that engage projections on a transducer, so as to draw the dome and transducer together. A given contact pressure is applied between the flexible membrane of the pressure dome and the diaphragm of the transducer. The apparatus described is useful in monitoring the blood pressure of a patient.
U.S. Pat. No. 2,866,453, granted Dec. 30, 1958 to Jewett, relates to a direct reading hypodermic pressure indicating device. The device comprises a syringe, a hypodermic needle, a manometer, a stopcock, and a fluid chamber having a flexible diaphragm thereacross. The needle and the syringe are connected to opposite ends of the stopcock; the manometer contains an indicating fluid and is connected to the fluid chamber which is also connected to the stopcock. By turning the handle of the stopcock, blood is directed into the fluid chamber to exert pressure on the diaphragm. The pressure is transmitted by the diaphragm to the indicating fluid in the manometer whose scale can be visually read.
U.S. Pat. No. 2,600,324, granted June 10, 1952 to Rappaport, discloses electrical circuitry for use with a transducer in a fluid pressure measuring system.